Like earthquakes, revolutions are much better at destroying than building. There is an important asymmetry here, whose roots go all the way down to the laws of physics: It is possible to change things quickly for the worse. It only took two hours after the collision between a 767 and the South Tower of the World Trade Center to destroy it. But no one can build the World Trade Center in two hours. The only thing you can do with Rome in a day is burn it.